Diseases of pre-weaning mortality in pigs
- Chaudhari1, Jai Bhagwan2, Vikram Jakhar3
1 Extension Specialist, Pashu Vigyan Kendra, Sirsa, 2Assitant Professor, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar
3Assitant Professor, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana
Pig farming in India is done by the persons belonging to lower socio economic groups. In India, most of the pig farmers prefer backyard farming. Pigs are let loose to feed in garbage dumps during the day time, thus they may expose to a variety of pathogens. Pig producers need to provide an environment that is optimal for the animal and in hospitable for disease-causing agents. As well as reducing infection pressure, immunity must be promoted by measures such as optimal nutrition and good husbandry. Prevention is obviously better than cure, and having a herd health plan will help to minimize disease incidence. Maintaining good biosecurity through every part of the production cycle will go a long way to preventing disease outbreaks. The control of diseases in the farrowing room helps prevent disease spread through other stages of production. Ideally, strong and healthy piglets will be weaned, as opposed to weak and infected piglets that would pass disease to pen-mates in the nursery. Endemic disease is controlled by maximizing piglet immunity and by minimizing the disease challenge. Neonatal immunity is dependent on all pigs receiving sufficient colostrum and a continuous supply of milk from their dam. The quality of protection can be enhanced by sow vaccination or by providing the sow with natural exposure to pathogens. Important enteric diseases are often controlled with the help of sow vaccination. In order to minimize the pathogen challenge to newborn piglets, the farrowing facilities need to be cleaned and disinfected between farrowings and operated in an all-in/all-out manner. In addition, good biosecurity is essential to prevent the introduction of a serious disease challenge to a herd that has no background immunity.
- Streptococcus suis infection
Streptococcus suis (S. suis) is regarded as a leading infectious disease in the swine industry and responsible for a wide range of diseases such as meningitis, arthritis, septicaemia, endocarditis, encephalitis, abortions, polyserositis and broncho-pneumonia, all of which have a negative effect on pig production. The disease most commonly causes meningitis and presents with fever, headache and vomiting. It may also present with skin bleeding and less commonly, sepsis, endocarditis, arthritis, bronchopneumonia and toxic shock syndrome. The characteristic complication of S.suis infection is deafness which is likely to remain permanent. S. suis infection is a common disease among pigs. The bacterium is carried in the upper respiratory tract of pigs, and spread among pigs by nose-to-nose contact or by aerosol over short distances. Apart from pigs (including wild boars), it can occasionally be found in other animals such as horses, dogs, cats and birds.
Human infection by S. suis occurs mainly in adults. It is transmitted through direct contact and often related to exposure through wounds on the skin while handling infected pigs or other animals, raw pork and other pig products. But it may also be transmitted via ingestion or through mucous membranes.
Strains of S. suis are divided into serotypes according to polysaccharide capsular antigens. Most S. suis isolates are sensitive to penicillin or cephalosporins. Treatment with high dose intravenous Penicillin G may be also highly effective in majority of patients.
2. Coccidia
Neonatal (baby pigs) coccidiosis caused by Isospora suis is found wherever pigs are raised in confinement. Clinical signs are of yellowish or gray pasty to liquid diarrhea appear at 1 to 2 weeks of age with dehydration evident even though nursing continues. Infection occurs in cells lining the small intestine. Oocysts (microscopic egg like forms) are passed five days after infection. Oocysts mature in 12 hours in the farrowing crate, and disease and mortality are directly proportional to the number of infective oocysts ingested. There has been no good evidence that sows are carriers and pass oocysts to their piglets. The source for this coccidian is still not known.
The other coccidia, Eimeria, which are found in weanling and older pigs, apparently cause little or no damage. Differentiation of Isospora from Eimeria can be made microscopically by laboratory diagnosis but coccidiosis in baby pigs is apparently Isospora only. Unfortunately, none of the anticoccidial drugs is effective against Isospora, but sanitation of farrowing crates by thorough cleansing can be successful in its control. Control is best achieved by:
- Thorough cleaning and sanitation between each farrowing
- Monitoring of movement of personnel and supplies
- Control of pests and rodents to reduce mechanical transmission of the oocysts.
- Colibacillosis
Colibacillosis, caused by pathogenic Escherichia coli, is one of the major causes of illness and death in piglets. Enteritis (enteric colibacillosis), which is associated with diarrhoea, occurs at three main periods of pig’s life; neonatal diarrhoea occurs at 0–4 days of age, neonatal – weaning diarrhoea at 4 days to 3 weeks and post-weaning diarrhoea of pigs at 5weeks of age.
- Greasy pig disease
Exudative epidermitis (EE) also known as greasy pig disease is an acute generalised disease of pigs caused by Staphylococcus hyicus. It affects pigs between the ages of a few days and roughly eight weeks. The clinical picture of EE is characterized by exfoliation of the skin, excessive sebaceous secretion and the formation of a brownish coat of exudates that may cover the entire body. Morbidity can be up to 90% in infected herds. All the affected animals showed the same progression of the disease, viz., a general loss of condition, exfoliation of the skin, excessive sebaceous secretion and the formation of a brownish coat of exudates that covered most part of the body especially around the face and shoulder region of the body.
- Swine brucellosis
Swine brucellosis is a zoonotic disease affecting pigs, caused by the bacterium Brucella suis. This species consists of five biovars, but infection in pigs mainly occurs due to B. suis Biovars 1, 2 or 3. Porcine brucellosis is of widespread occurrence; however, prevalence is low, with the exception of South America and Southeast Asia where high prevalence has been reported (OIE, 2009). In India, porcine brucellosis has been found to be associated with production losses in pregnant sows. It has acute bacteremia, symptoms can vary depending on the area of localization. Common manifestations are abortion, temporary or permanent sterility, orchitis (swollen testicles), lameness, posterior paralysis, stillborn, mummified or weak piglets. Brucella suis is transmitted mainly via ingestion of infected tissues or fluids. Infected boars may transmit the disease during service; the organism can be recovered from semen. Brucellosis in humans has been reported among packing-house workers and hunters; the usual source is infected pigs.
- Piglet anemia
It is highly fatal disease of suckling pigs caused by a marked decrease in hemoglobin and fatty degeneration of the liver. The newborn piglet has only limited reserve of iron in the liver for hemoglobin synthesis. This is due to poor placental transfer of iron to foetus. The newborn piglets contain only about 50 mg of iron stored mainly in liver and their daily need is about 5 to 10 mg. The sow milk is very low in iron and the suckling pig should be supplemented with iron during first few days to prevent piglet anaemia. Fresh clean soil is one of the sources for iron but indoor rearing under concrete flooring prevents the piglets access to fresh soil.
